#include"alloc.h"
#include"stdio.h"
struct x
{
int data;
struct x *link;
};
typedef struct x node;
node *start;
void main()
{
node *x;
int ch;
x=(node*)malloc(sizeof(node));
start=x;
clrscr();
printf("Enter data:");
scanf("%d",&x->data);
x->link=NULL;
do
{
x=start;
clrscr();
display(start);
printf("\n\nEnter your choice:\n1. Insert First\n2. Insert Last\n3. Insert Between\n4. Delete First\n5. Delete Last\n6. Delete Between\n7. Delete All\n8. Exit\n");
scanf("%d",&ch);
if(ch==1)
get(x);
if(ch==2)
getrev(x);
if(ch==3)
getmid(x);
if(ch==4)
delfirst(x);
if(ch==5)
dellast(x);
if(ch==6)
delmid(x);
if(ch==7)
delall(x);
if(ch>8||ch<1)
{printf("\n\tInvalid Choice\n\tEnter again....");getch();}
}
while(ch!=8);

}
/* E N D  O F  M A I N  P R O G R A M*/

get(node *z)
{
node *new;
new=(node*)malloc(sizeof(node));
printf("Enter data:");
scanf("%d",&new->data);
new->link=z;
start=new;
return;
}

getrev(node *a)
{
node *st,*prv;
while(a)
{
prv=a;
a=a->link;
}
prv->link=(node*)malloc(sizeof(node));
prv=prv->link;
printf("Enter data:");
scanf("%d",&prv->data);
prv->link=NULL;
return;
}

getmid(node *m)
{
int x=1,n;
node *new,*prv;
new=(node*)malloc(sizeof(node));
printf("Enter data:");
scanf("%d",&new->data);
printf("Enter the location:");
scanf("%d",&n);
while(n>x)
{
prv=m;
m=m->link;
x++;
}
prv->link=new;
new->link=m;
return;
}

delfirst(node *f)
{
node *prv=f;
if(f==NULL)
{
printf("\nNode not found");
getch();
return;
}
start=f->link;
free(prv);
return;
}

dellast(node *l)
{
node *prv;
if(l==NULL)
{
printf("\nNode not found");
getch();
return;
}

while(l->link)
{
prv=l;
l=l->link;
}
prv->link=NULL;
free(l);
return;
}

delmid(node *m)
{
node *prv,*prv1;
int n,x=1;
printf("Enter the location:");
scanf("%d",&n);
while(x<n)
{
prv1=m;
m=m->link;
x++;
}
prv=m;
m=m->link;
prv1->link=m;
free(prv);
return;
}

delall(node *a)
{
node *prv;
if(a==NULL)
{
printf("\nNode not found");
getch();
return;
}

while(a)
{
prv=a;
a=a->link;
free(prv);
}
start=NULL;
return;
}

display(node* p)
{
while(p)
{
printf("\n%d",p->data);
p=p->link;
}
return;
}